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HQMcDONOUGH.

' Damper. NO 66.16]. Patented June 25,1867;

" HHHk ra m 7 w y m ER, .WGTONM. V j {I HENRY MCDONOUGH, OF NEW YORK, N. Y.

Letters Patent No. 66,161, dated June 25, 1867.

DAMPER IN STEAM BOILERS.

flip fittebulr march tn in that) Eaters fitment amt mating put at tip-same;

- TO ALL WHOM IT MAY CONCERN:

Beit known that I, HENRY MCDONOUGH, of the city, county, and State of New York, have invented a. new and useful improvement in Steam Boilers and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable othersskilled in the artto make and use the same, reference being had to the accompanying drawings forming part of this specification.

This invention consists in the arrangement of valves at the ends of a tubular steam boiler, in such a manner that the heated gases and products of combustion are retarded and detained in their passage to the chimney, and thereby compelled to part with their caloric, as "will be hereinafter described.

Figure 1 represents a vertical longitudinal section of a tubular steam boiler with my improvement applied.

Figure 2 is a cross-section through the line it a: of fig.

Similar letters of reference indicate like parts. A

i A represents the boiler, and B the tubes of the boiler C is the boiler arch, and C is a partition over the furnace-grates, which conducts the blaze and products of combustion under the boiler. It is designed to apply my improvement to marine boilers as well as stationary boilers. In marine boilers the arch would be the same or similar, and represented by a water front and water-log, as is usual in these boilers. Suitable provision would be made in either case for the passage of the rod or any other part of the fixtures pertaining to my improvement through the walls. D isa valve at the front end of the boiler, and E is anothervalve at the back end. These valves when closed, as in the drawing, stop the passage of the products of combustion past them entirely. They are hung on pivots, seen atf, upon which they'turn in opening and closin The upper portion of each valve is weighted, so that only bei'ng'opcned as far as is seen in the red lines, or not quite per pendicnlar, the preponderance of weight on the upper portion closes the valve without effort on the part of the attendant. The two valves are connected together by chains, which, in this example of my invention, pass through the lower tubes, but I do not confine myself to this particular method. The pivots may be made to pass through the walls or water-legs, and the valves be connected by chains or rods and cranks on the outside, or in any other convenient manner. In this case, as before stated, the valves are connected by chains which pass over pulleys, and which are attached to the valves by staples, as'seen in the drawing. a represents the chains, 6 the pulleys, and c the staples; 11 represents the weight attached to the valves. G'is a rod attached to the front valve D by a staple. The rod G passes through the wall, and by which the valves are operated. It will be noticed that this rod G is attached to the valve below the centre or pivot, so that when the rod is pushed in the weighted portion of the valve is raised, and the valve assumes the position scan in red. The

. chains are attached to each valve on each side of the pivot. The chain a in front-is a at the back end, and it will be seen that the eff ct of opening the front valve will be to open the back one. The other chain a. being i attached in the same manner, closesthe valve in case the weight does not do it. The heated gases and products of combustion will pass under the'boiler, as indicated in the drawing, and return to the front through the lower tubes, or through those tubes which lie below the back valve. From the chamber under the front valve they enter the tines abovc, or those marked g,-and return to the back end into the space above the backvalve. From thence. they are compelled to return to the front through the upper tubes, from whence they are discharged into the chimney. I i

It will thus be seen that the heat passes three times through the tubes of the boiler. In the meet tubular boilers a difiiculty has always been experienced in consequence of the tendency of the heat to ascend to the upper tubes, and many devices have been resorted to to force the most of the heat through the lower tubes, but these efforts have hitherto been only partially successful. This desirable object is accomplished by my invention, as will be seen. I Upon starting the fire the valves would be opened so'that there would be a frce.;draugl1ti his only where there is a suflicicncy of steam that the valves would be closed and the heat retained-as proposed. The'walvcs being at all times underthe control of the fireman, can be opened inwhole or in part at any time to increase the draught.

What I claim as new, and desire to secure by Letters Patent, is*

The valves 1) and E, arranged and operating substantially as herein shown and described, in combination with a tubular steam boiler-,for the purposes specified.

r The valve E, opened and closed by means of the weight cl and chainsa a, operated from the valve-l) by the rod Gr, as herein set 'forth for the purpose specified.

I claim the partition plate 0, in combination with the valves for the purpose set forth.

. HENRY McDONOUGH. Witnesses:

Win. F. MeNAMans,

ALEX. F. Ronnn'rs. 

